Sometimes you notice analogies between things that at first seem very disparate. For example, on many long running TV shows, there is a character who is the backbone of the show. The personality of this character is generally more or less predictable and on the nose.
And then there is another character who weaves around this first character in a way that is quirkier and less predictable. Somehow, for reasons you don’t completely understand, you find you can’t take your eyes off of this other character.
This supposedly secondary character is in some ways more important than the titular central character, because he or she represents the dynamic arc, the evidence of travel, the long journey that the audience has been invited to take.
With that in mind, I present the following analogy:
Don Draper is to Peggy Olson as Buffy Summers is to Spike.
I imagine you can think of others.